This study was aimed to evaluate the effectiveness of CAI vs. classroom lecture for computer science at ICS level. The objectives were to compare the learning effects of two groups with class room lecture and computer assisted instruction studying the same curriculum and the effects of CAI and CRL in terms of cognitive development. Hypothesis of this research were based on six levels of blooms taxonomy as there was one major hypothesis: There is no significant difference exist for CAI student in gaining a high cognitive achievement than students of same level having Traditional CRL. The study was delimited to three colleges of Faisalabad city. The research was true-experimental in nature. The research design followed by researcher is The Pre-test-Post-test Equivalent groups Deign. The software used for CAI group was basically the combination of Discovery environment and simulation softwares, however, the time for drilling and practice was given to student. It a designed to cover the all levels of cognitive domain described by B. S. Blooms (1956). A question paper containing 30 items multiple choice test was compiled from the curriculum, with a representative number of questions from each of the cognitive levels. Findings of this research indicate that total gain in cognitive domain by CAI was significantly superior to the total gain in cognitive domain by CRL teaching method. This study concluded that the skills of knowledge, analysis and synthesis assured significant increase. The CAI proved to be very much effective in increasing the evaluation and application skills of students to experimental group. Comprehension skill, however, not much affected by the CAI. According to the results of this study it was suggested that CAI as an effective teaching method should be applied to improve teaching quality and by using CAI it will be possible to eliminate lingual, regional and ethical biases between teacher and student.